FPRL2 is known as one of orphan G protein-coupled receptor proteins (Genomics, 13 (2), 437-440 (1992)).
As an agonist for FPRL2, Trp-Lys-Tyr-Met-Val-Met-NH2 (SEQ ID NO:8) as a synthetic peptide is reported. It is also reported that FPRL2 is highly expressed in monocytes (J Biol. Chem., Jun. 15, 2001; 276 (24): 21585-93).
GHRP-6 is known as a synthetic GHS (growth hormone secretagogue) peptide (Science, Aug. 16, 1996; 273 (5277): 923).
SCPA is a neuropeptide derived from sea hare or Aplysia and reportedly associated with regulation of heart beats (Proc. Natl. Acad. Sci. USA, June 1985; 82(11): 3925-3929).
RFRPs such as RFRP-1-12, etc. have been reported to have a prolactin secretion stimulating action, etc. (Biochim. Biophys. Acta, Sep. 26, 2001; 1540(3): 221-32).
Neuropeptide Y (NPY) is known to be involved in regulation of eating behavior, regulation of biological rhythm, depression or anxiety, and other higher mental functions (ZUKAI HORMONE-NO-SUBETE (Illustrated All About Hormones), 1998, Igakunosekaisha, Inc., Section entitled NPY (pages 152-164).
Neuromedin C has been reported to be a bombesin-like peptide (Biochem. Biophys. Res. Commun., Feb. 29, 1984; 119(1): 14-20).
The present invention intends to identify a novel ligand for FPRL2 and provide use of FPRL2 and its ligand. That is, the present invention intends to provide a method of screening a compound (antagonist or agonist) or a salt thereof that changes the binding property of a ligand peptide to FPRL2, a kit for said screening, a compound (antagonist or agonist) or a salt thereof that changes the binding property of a ligand peptide to FPRL2 obtained by the screening method or the screening kit, and a pharmaceutical comprising a compound (antagonist or agonist) or a salt thereof that changes the binding property of a ligand peptide to FPRL2, and the like.